Is this your situation?
You feel you have a product or service so good that you are actually doing people a favour telling them about it. So you want to send out emails to customers and potential customers telling them all about it.

No matter how wonderful you think the information is, unless you follow some rules what you send will be SPAM. Sending spam can easily result in your website being closed down along with your email address(es) - and in extreme cases heavy fines and even imprisonment.

The rules to follow are: 

- your subscribers must have asked to be on your list by the 'opt in' method. NOT 'opt out' where recipients are considered to be on your list unless the say no.
This means that simply having someone supply their email address is not enough, the address might not be submitted by the rightful owner. You must verify email addresses and receive permission to use the address in your mailing. All good email list systems will do this for you automatically.

- you must provide with every mailing a clear, obvious and simply way to un-subscribe (or 'opt-out') from your list.

- you must make it completely clear who is sending the mass emailing and provide a reply email address as well as a physical address.

- you must make it completely clear why the recipient is getting your email (You are receiving this email because you subscribed to...)

- you must make it completely clear that what you are sending is an advertisement or promotional material.

Not rules, but good manners...

We do not recommend sending mass mailing by other methods than an 'emailing list system' (as opposed to your email client like Outlook). This list system can be a third party mailing system where you pay per mailing or as part of your website.

If you do use your email client do NOT send all your list as 'cc' (carbon copy). This means your email list is sent to every subscriber. So not only are you giving away your valuable email list, you are opening every one of your subscribers to the dangers of spam. It only takes one subscriber to click 'Reply All' to use your list for whatever purposes they want.
So use instead 'bcc' (blind carbon copy) if you must use your email client. The 'to' field can use your email address or 'undisclosed recipient'.

Remember that sending 'rich test format' (actually HTML) emails will require more time and bandwidth to send and more space on the recipients' computers. Do you really need coloured fonts, product images and logos in your mailings - and do you know how to send such emails so they appear correctly?

It is always better to write short, fresh, original mailings when you have something genuinely interesting and important to say, rather than battering your list with stale sales patter every week, which will be counter productive.